The 2018 flu season has been especially rough on Americans—this year’s dominant viral strains have led to more hospitalizations and doctor visits than almost any other in the past decade.

Despite the incredible advances being made in medical science, so much of our nation’s health still depends on effective planning: not just choosing the ‘correct’ vaccine for mass production, but getting it to the right people at the right time.

A group of simulation experts at the Biocomplexity Institute of Virginia Tech demonstrated that models which fail to accurately reflect the conditions of economically disadvantaged citizens often overestimate the effectiveness of governmental health interventions such as vaccination by 30 to 55 percent. With the cost of flu season already staggeringly high—over $10 billion in the U.S. alone according to CDC reports—such a sizable swing in accuracy could major economic impacts.

This first-of-its-kind study builds on more than a decade of Biocomplexity Institute research developing “synthetic populations” where individuals move, interact, and respond to stress just like people in real-world communities. These simulated societies capture unique factors in the day-to-day lives of low-income families that place them at a higher risk of infection during disease outbreaks.

“Using data on people living in the ‘slum’ neighborhoods of Delhi, India, we discovered that typical dwellings have a single room and very high occupancy rate, both of which significantly increase opportunities for disease transmission,” said Achla Marathe, professor at the Biocomplexity Institute and the Department of Agricultural and Applied Economics in the College of Agriculture and Life Sciences. “Those factors, combined with a work life that doesn’t typically allow for sick days makes quarantining nearly impossible and vaccination particularly crucial.”

With an estimated 80 million Americans living or traveling outside the country each year, Virginia Tech researchers believe their study could have a major impact on the way governments prepare for outbreaks, both at home and abroad.

“This project has set up a solid foundation for further studies into how epidemics work, not just at the national or state level, but among specific sub-sections of the population,” said Chris Kuhlman, a research scientist in the Biocomplexity Institute’s Network Dynamics and Simulation Science Laboratory. “The data have shown us that different economic groups in the same city can experience disease outbreaks in drastically different ways—now the tools we use to plan our response can reflect that.”

“Global epidemics like flu, Zika, and Ebola are constantly reminding us that, no matter where we live, our health is connected to communities across the world,” said Marathe. “The more we know about how our neighbors are likely to be affected by a disease, the better prepared we can all be to fight it.”

The Biocomplexity Institute regularly conducts research through federal, state and industry grants and contracts. This research, made possible through the support of the National Institutes of Health and National Science Foundation, is part of the institute's portfolio of research programs that has received more than $103M in new awards in the first half of FY 2018.